Influence of a boron distribution on profiles of defects in silicon irradiated by light ions

Changes in electric conductivity of strong-doped p-Si irradiated by H+ and B+ ions at 40-100 keV energies are studied. The p-type layers with the inhomogeneous boron depth distribution are preliminarily formed by diffusion or implantation. Irradiation and electric conductivity measurement are carried out at room temperature. Usually ion irradiation is followed by formation of radiation defects decreasing electric conductivity. However, the depth distribution of these defects, as it turned out, can significantly differ from the profiles of elastic energy losses. Depending on the distribution of the initial impurity the radiation defect profile can have additional peaks near the surface or in the depth, which are not coincide with the peak of elastic energy losses. The possible causes may be diffusion, defect migration in an elastic electric field and the increase of complex formation efficiency in areas with the increased impurity concentration. It is assumed that the main channel of electric conductivity ''turn-off'' is complex formation with boron atoms